The Trump administration waived an arcane law after heavy criticism about the delayed response to Puerto Rico after Hurricane Maria.

The Trump administrationannounced Thursday morning it would temporarily waive the Jones Act, a nearly-century old law limiting international shipping in Puerto Rico. Eight members of Congress asked the administration on Monday to temporarily waive the law in order to permit the import of life-saving reliefafter Hurricane Maria.

“It is an act of justice,” said Carmen Yuliín Cruz, the mayor of San Juan, said on CNN on Thursday. “It will allow Puerto Ricans to rebuild and to have a cost of living that really frankly is affordable.”

The law was put in place in 1920 and makes it twice as expensive to ship things from the U.S. mainland to Puerto Rico as it is to ship from any other port in the world. Basic shipments of goods from the mainland to the island and vice versa are conducted via protected ships rather than exposing them to global competition. This same law is one of the primary reasons why Puerto Rico is in such a severe financial crisis in the first place, as it drives up cost of living on the island overall.

The act was quickly lifted to help Texas and Florida in the wake of Hurricane Harvey and Irma. The Department of Homeland Security said it was able to lift the restrictions quickly because the Department of Defense requested a waiver for those states but hadn’t done so for Puerto Rico. The waiver will be in effect for 10 days.